20895983 has 4 divisors (see below), whose sum is σ = 21804528. Its totient is φ = 19987440.

The previous prime is 20895929. The next prime is 20896013. The reversal of 20895983 is 38959802.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20895983 - 2¹⁸ = 20633839 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20895883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 454238 + ... + 454283.

It is an arithmetic number, because the mean of its divisors is an integer number (5451132).

Almost surely, 2^20895983 is an apocalyptic number.

20895983 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

20895983 is a deficient number, since it is larger than the sum of its proper divisors (908545).

20895983 is an equidigital number, since it uses as much as digits as its factorization.

20895983 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 908544.

The product of its (nonzero) digits is 155520, while the sum is 44.

The square root of 20895983 is about 4571.2124212292. The cubic root of 20895983 is about 275.4361475775.

The spelling of 20895983 in words is "twenty million, eight hundred ninety-five thousand, nine hundred eighty-three".